Eleven seamen abandoned their 250-foot ship before it sank in the stormy Atlantic, and four were rescued but the others were missing Thursday, including a crewman who slipped through his life jacket, authorities said.

Shortly before 5 a.m., Coast Guard frogmen jumped from a helicopter and saved two men who were drifting without rafts in the water. They were then pulled aboard the copter, said Coast Guard Lt. Paul Wolf.The two were to be transported to a Falmouth hospital. One had possibly serious injuries, but both were conscious and alert, Wolf said.

Rescuers were hampered by heavy rains and 40- to 45-mph winds and 20- to 25-foot seas.

After searching for two hours, a Coast Guard jet spotted a life raft with an unknown number of survivors. A helicopter was dispatched to try to pick them up, said Coast Guard Petty Officer Kenneth Arbogast.

The ship, the Lloyd Bermuda, sank about 160 miles south of Nantucket and 200 miles east of New Jersey.